Many conventional food products are prepared and sold in the form of foodstuff portions that are coated with batter or with a layer of batter that is itself coated with breadcrumbs or a granular composition resembling breadcrumbs. Conventionally the former are known as "battered" foodstuffs and the latter as "breaded" foodstuffs. Generally, such coated foodstuffs are marketed in a substantially uncooked state and the consumer prepares them for consumption by, for example, deep or shallow frying.
Traditionally it has been found necessary to heat-set the batter in the coating after it has been applied to the foodstuff. Heat-setting imparts to the coated foodstuff sufficient cohesion and robustness for the coated foodstuff to be handled during subsequent operations, such as packaging, prior to deep freezing and ensures that the batter remains stable and cohesive if the coated foodstuff subsequently thaws.
Conventionally, heat-setting of the batter is performed by frying the coated foodstuff briefly in hot oil. For example, in a conventional process for producing fish fingers, individual fish sticks (prepared by sawing a block of frozen fish) are battered and breaded, and then fried at 180.degree. C. for 30 to 40 seconds, before being packed and refrozen.
Heat-setting of the batter by frying has several inherent disadvantages. Oil is absorbed during frying and this tends to produce an unnecessarily high level of oil (6-7%) in the coated foodstuff. Moreover, it is often necessary to discard some or all of the oil because it undergoes thermal degradation. Hence, frying is expensive because the high grade oil must be replenished continuously.
It is thus desirable to be able to find novel processes for selectively heating the outer surface of food products in order to be able to heat-set coatings.